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Courier can send the same notification in multiple languages. In Design Studio, you write content once in a default language, add locales, and let AI translate each field. When you update the source copy later, Courier flags outdated translations so you can refresh them in one click. This tutorial walks through the full flow: open the translation editor, add a locale, review AI-generated translations, and keep them in sync when your default content changes. Prefer to manage translations in code? Use the localization API instead.

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Add a locale

Open your template in Design Studio, then click the globe icon in the toolbar (Manage localization and translations). The Add locale modal opens.
AI Translate Button
Search for your target language and select it.
Translate Flow Choose Language
Check Translate with AI to generate translations automatically when you add the locale. You can also translate manually or run AI translation later from the review screen.
Translate Flow Language Selected
Click Add. Courier creates the locale and runs AI translation across all translatable fields in the template, including email subjects, body text, and button labels.

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Review translations

After translation completes, the review screen shows a side-by-side table: Default on the left, your target locale on the right. Each row maps one content field (subject line, paragraph, call-to-action, and so on).
Translations Review Screen Translations Complete
Use the locale list in the sidebar to switch between languages. The status badge at the top shows how many fields are translated for the active locale. To preview how a locale renders, click Preview. Edit any field directly in the right column if you want to adjust the AI output before publishing.
AI translation preserves variables in your template. Review fields that contain dynamic placeholders to confirm the translated text still reads naturally around {variable} tokens.

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Update outdated translations

When you change content in the default language, Courier marks existing translations as outdated. The review screen highlights the changed source string and shows a warning on the affected translation.
Translations Review Screen String Out Of Date Needs Translation
Click the Translate all button (or the per-field AI action) to re-translate outdated fields. Courier uses the current default text as the source and updates the locale in place. You can also translate individual fields without re-running the full locale.

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Send localized notifications

Courier picks the right locale at send time based on the recipient’s profile or the locale field in your send request: 
{
  "message": {
    "to": {
      "email": "user@example.com",
      "locale": "es"
    },
    "template": "TEMPLATE_ID",
    "data": {
      "name": "Alex"
    }
  }
}
To verify before sending, create a test event with a locale on the profile. The preview shows the localized version instead of the default language.

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What’s next

Localization API

Push translations from a script or translation management system.

Localization reference

Locale formats, RTL support, and full API details.

Handlebars formatting

Format dates and numbers for a user’s locale.

Send conditions

Route to channels based on locale or other profile data.